I have written an extension function:

public static TSource MaxBy<TSource>(this IEnumerable<TSource> sequence, params Func<TSource, float>[] selectors)
{
    for (var i = 0; i < selectors.Length - 1; i++)
    {
        var indexed = sequence.Select(x => (element: x, value: selectors[i](x)));
        sequence = indexed.Where(x => x.value == indexed.Max(y => y.value)).Select(x => x.element);
        //`sequence` contains: 18, 25
    }
    //`sequence` contains: 75
    //Last function
    if (selectors.Length > 0)
        return sequence.MaxBy(selectors[selectors.Length - 1]);
    else
        throw new ArgumentOutOfRangeException();
}

However, this function does not work as intended. The value of sequence unintentionally changes between the end of the last iteration of the loop, and after loop exit. What is causing this behavior and how to deal with it?

Tried var temp = sequence but it also does not help.